The class of linear alternating polymers of carbon monoxide and ethylenically unsaturated compounds is now well known in the art. Such materials are characterized by a structure having the repeating formula ##STR1## wherein A is a moiety of at least one ethylenically unsaturated compound polymerized through the ethylenic linkage thereof. Although the scope of the process of producing such polymers is extensive, the process typically comprises contacting the carbon monoxide and ethylenically unsaturated compound in the presence of a catalyst composition formed from a compound of a Group VIII metal, preferably selected from palladium, cobalt or nickel, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus, arsenic, antimony or nitrogen. For the polymerization of most ethylenically unsaturated hydrocarbons, a catalyst composition wherein the metal compound is a compound of palladium and the bidentate ligand is a ligand of phosphorus is preferred. See, for example, van Broekhoven et al, U.S. Pat. Nos. 4,880,903, and 4,843,144. In most cases, the use of a bidentate phosphorus ligand wherein each monovalent phosphorus substituent is aromatic is particularly preferred.
For the polymerization of certain ethylenically unsaturated compounds, the use of the generally preferred bis(diarylphosphino)alkane ligands does not give entirely satisfactory results. When linear alternating polymers of carbon monoxide and styrene are desired, it has been found that bidentate ligands of nitrogen such as 2,2'-bipyridine are preferred and bidentate phosphorus ligands are not suitable. See, for example, U.S. Pat. Nos. 4,788,279 and 4,965,341.
When linear alternating polymers of carbon monoxide and a non-conjugated alkenyl benzene compound such as allylbenzene are desired, it has been found that neither the bis(diarylphosphino)-alkane or the bidentate nitrogen ligands provides satisfactory results. It would be of advantage to provide a better process for the production of linear alternating polymers of non-conjugated alkenylbenzene compounds.